Diastereoface differentiation in addition of lithium enolates to chiral α,β-epoxyaldehydes
作者:Jean-Marc Escudier、Michel Baltas、Liliane Gorrichon
DOI:10.1016/s0040-4020(01)82375-9
日期:1993.6
aldolisation reaction of lithium ester enolates with chiral α,β-epoxyaldehydes 2a–2f has been investigated. The reaction proceeds with diastereofacial preference in favour of the anti isomer (anti:syn ≈ 4:1) and can be greatly enhanced in the case of cis α,β-epoxy-aldehydes 2a–2c by a synergic effect of temperature and enolate excess (anti:syn 13:1). The Felkin-Ahn model can explain the results obtained
已经研究了酯酸锂与手性α,β-环氧醛2a–2f的醛醇缩合反应。反应以非对映体优先进行,有利于抗异构体(anti:syn≈4:1),在顺式α,β-环氧-醛2a–2c的情况下,温度和烯醇过量的协同作用可以大大增强反应(反:syn 13:1)。Felkin-Ahn模型可以解释在不对称感应下获得的结果。